Arboretum Systems Hyperprism-DX User Manual

Hyperprism-DX for DirectX Plug-in compatible applications

Digital Audio Signal Processing Software by Arboretum Systems Inc.
This documentation current for Hyperprism-DX version 1.5.5, last updated 11/19/98.
Copyright ©1997, 1998 by Arboretum Systems, Inc. This Documentation may not, in whole or in part, be copied,

reproduced or translated without prior written consent of Arboretum Systems.

What's New in Hyperprism-DX v1.5.5:

New Harmonic Exciter, Bass Maximizer and Tube/Tape Saturation effects●
Automatic uninstalling of older versions for easy upgrading.●

New in Hyperprism-DX 1.5.1:

New Vocoder, Frequency Shifter, HyperVerb, M-S Matrix and Limiter effects.●
Improved Compressor, Pitch Changerand Filters for better sound and easier use.●
Improved Install/Deinstall process.●
Dongle copy protection eliminated! Now it's just a simple serial number.●

Contents

Software License Agreement●
Introduction●
Installation●
Controlling Hyperprism●
Using Presets●
Effects Processes

Filters❍
Modulators❍
Delay Processes❍
Stereo Effects❍
Miscellaneous Processes❍

●

Troubleshooting●
About Digital Audio Files●

About This Manual

The documentation may be viewed or printed from any browser, such as Netscape Navigator or Microsoft Internet
Explorer. If the text is too small or you wish to change the background color, go into your browser's Preferences and set
them as you wish. Internet Explorer users, just hit the Larger button on your browser tool bar.

Important: For better scrolling comfort use the scroll bar, or the page up/page down keys, rather than the up and down
arrows.

Manual Conventions

Throughout this manual, you will see several different symbols in sections describing step-by-step operations.

Text following a right pointing arrow

invites you to execute a command with the mouse or keyboard.

Text following a down pointing arrow

describes the result produced by executing a command.

A pointing hand

indicates an important note!

Documentation current for Hyperprism-DX version 1.5, last revised 11/19/98. Manual written and edited by Todd
Souvignier with contributions from Aram Lindahl and Chris Townsend, plus legacy material by Georges Jaroslaw, Chris
Weare, Curtis Roads and David (Rudy) Trubitt. Hyperprism-DX engineering by Daniel Habault and Chris Townsend with
Jarret Cooper, under the supervision of Chris Weare.

For any questions, either reach us at the web site (http://www.arboretum.com), call us at [phone] or send us an
email at: [e-mail]

This documentation current to Hyperprism-DX version 1.5.5, last revised 11/19/98
Copyright ©1997, 1998 by Arboretum Systems, Inc. This documentation may not, in whole or in part, be copied,

reproduced or translated without prior written consent of Arboretum Systems.
Arboretum Systems Inc. 75 Aura Vista, Pacifica California 94044

[Go to First Chapter]

Hyperprism-DX for DirectX Plug-in compatible applications

ARBORETUM SYSTEMS SOFTWARE LICENSE AGREEMENT

Please read these terms carefully before opening the sealed diskette package, as opening such package will indicate your agreement to these terms.

Arboretum Systems ("Arboretum") is willing to license the enclosed Hyperprism software ("Software") only upon the condition that you accept all the terms of this
Agreement. If you do not agree to these terms, then Arboretum is un willing to license the Software to you, in which event you must return immediately, and in no
case later than ten (10) days from the date of purchase, the unopened diskette package (and accompanying items including manual, other documentation and
container) together with your proof of purchase, to the place from which it was acquired for a refund.

LICENSE: You may use the enclosed Software on a single computer. The Software is in use when it is installed into permanent memory (such as a hard disk or
other storage device) or loaded into temporary memory (RAM) of that computer. The Software is copy protected.

RESTRICTIONS: You may not transfer, modify, rent, lease, loan, resell, distribute, network, electronically transmit or merge the Software. You may also not
reverse engineer, decompile or disassemble the Software, or otherwise attempt to discover the Software source code. You are not permitted to copy the Software
(except to make an archival copy for back-up purposes) or any of the accompanying documentation. Any attempt to transfer any of the rights, duties or obligations
here under except as expressly provided for in this Agreement is void.

COPYRIGHT: The Software (including audio, music, text, images and animations incorporated into and accompanying the Software) and accompanying
documentation are owned by Arboretum or its suppliers and are protected by United States copyright laws and international treaties. Unauthorized reproduction or
distribution of the software or documentation is subject to civil and criminal penalties.

LIMITED WARRANTY: Arboretum warrants for the period of thirty (30) days from the date of delivery of the Software to you, as evidenced by a copy of your
receipt, that: (1) The Software will perform substantially in accordance with the user documentation provided by Arboretum. Your sole remedy under this warranty
is that Arboretum will, at its option, either repair or replace the Software which does not meet this Limited Warranty, or refund to you the money paid for the
Software. Arboretum does not warrant that the Software will meet your requirements, that operation of the Software will be uninterrupted or error-free, or that all
software errors will be corrected. (2) The medium on which the Software is furnished will be free from defects in materials and workman ship under normal use.
Arboretum will, at its option, either repair or replace the faulty medium at no charge to you, provided you return the faulty medium with proof of purchase to
Arboretum.

This Limited Warranty is void if any failure of the Software or any damage to the medium is due to accident, disaster, abuse, misapplication, modification of the
Software and/or violation of any of the terms of the License Agreement.

The above warranties are exclusive and in lieu of all other warranties, express or implied, and Arboretum expressly disclaims all other warranties, including the
implied warranties of merchantability, fitness for a particular purpose and non-infringement. No oral or written information or advice given by Arboretum, its
employees, dealers, resellers, distributors or agents shall increase the scope of the above warranties or create any new warranties. Some states do not allow the
exclusion of implied warranties, so the above exclusion may not apply to you. In that event, any implied warranties are limited in duration to thirty (30) days from
the date of delivery of the software. This warranty gives you specific legal rights.You may have other rights, which vary from state to state.

LIMITATION OF REMEDIES: Arboretum's entire liability to you and your exclusive remedy shall be the repair or replacement of the Software, the repair or
replacement of the Software medium, or the refund of your purchase price, as set forth above. In no event shall Arboretum's liability to you or any third party
exceed the purchase price paid for the Software.

Regardless of whether any remedy set forth here in fails of its essential purpose, in no event will Arboretum or its authorized dealers, resellers or distributors be
liable to you (1) for any damages, including any lost profits, lost data, other incidental or consequential damages, arising out of the use or inability to use the
Software or any data supplied there with, even if Arboretum has been advised of the possibility of such damages, or (2) for any claim by any other party. Some
states do not allow the limitation or exclusion of liability for incidental or consequential damages so the above limitation or exclusion may not apply to you.

GENERAL: This Agreement will be governed by the laws of the State of California, except for that body of law dealing with conflicts of law. If any provision of
this Agreement is held to be unenforceable, that provision will be removed and the remaining provisions will remaining full force. This Agreement is the complete
and exclusive statement of the agreement between us which supersedes any proposal or prior agreement, oral or written, and any other communications between us
in relation to the subject matter of this Agreement. If you have any questions concerning this Agreement, you may contact Arboretum by writing to Arboretum
Systems, 75 Aura Vista, Pacifica California 94044. Hyperprism is a trademark of Arboretum Systems.

You acknowledge that you have read this Agreement, understand it, and agree to be bound by its terms.

[Table of Contents] [First Chapter]

Hyperprism-DX

Welcome to Hyperprism-DX

Hyperprism-DX is a set of high-quality audio plug-in effects. More than thirty different sound processing modules,
tailored for the needs of electronic music production, film/video post and multimedia audio production. Each can be used
from within any Windows 95/98/NT 4.0 sound editing program that supports the Microsoft DirectX plug-in format (also
variously known as ActiveMovie and DirectShow). Applications currently supporting DirectX audio plug-ins include
Cakewalk, Cool Edit Pro, Cubase VST, Logic Audio, Sound Forge, Studio Vision and WaveLab.

Hyperprism-DX (also sometimes referred to as H-DX or simply Hyperprism) is a component of the Hyperprism Plug-in
Pack. Plug-in Pack also includes editions of Hyperprism for the MacOS VST and AudioSuite and Premiere plug-in
formats.

Refer to your sound editing program's manual for instructions on installing and opening DirectX audio processing
plug-ins, such as Hyperprism-DX. Also be sure to read on to the next chapter in this document, Installation, for

step-by-step setup instructions, and tips on getting running.

Hyperprism-DX Processes

Click on any link below for detailed description of each Hyperprism effect.

Hyperprism Filter Processes

Low Pass●
High Pass●
Band Pass●
Band Reject●

Hyperprism Modulation Processes

Vocoder●
Frequency Shifter●
Phaser●
Flanger●
Chorus●
Ring Modulator●
Tremolo●
Vibrato●

Hyperprism Delay and Reverb Processes

Single Delay●
Multi Delay●
Echo●
HyperVerb●
Room Reverb●
Hall Reverb●

Hyperprism Stereo Processes

Pan●
Auto Pan●
Quasi Stereo●
Stereo Dynamics●
More Stereo●
M-S Matrix●

Hyperprism Miscellaneous Processes

New! Harmonic Exciter●
New! Bass Maximizer●
New! Tube/Tape Saturation●

Pitch Changer●
Noise Gate●
Compressor●
Limiter●
Sonic Decimator●

System Requirements

Hyperprism-DX requires a Pentium computer, 133 MHz or faster with Windows 95, Windows 98 or Windows NT 4.0 and
one or more audio editing programs which support the Windows DirectX (a.k.a. ActiveMovie or DirectShow) plug-in
format. Applications currently accepting DirectX audio plug-ins include Cakewalk, Cool Edit Pro, Cubase VST, Logic
Audio, Sound Forge, Studio Vision and WaveLab.

About Hyperprism-DX

Hyperprism can be thought of as a "rack" of studio-quality effects processors. Each effect in the package can be selected
from a menu in the host application, previewed and adjusted in real-time and applied individually to any track, region or
file. Depending on the level of DirectX implementation in your "host" sound editing software, effect processing may
"rendered" off-line, outside of real-time, or effect processing may happen in-line, processing audio tracks in real-time.

Any effect parameter can be made to follow the movement of the mouse in the Blue Window. Once you have assigned
effect parameters to mouse movements, simply click and drag the mouse within the Blue Window. As you do so, you'll
hear and see the results; as your sound is being previewed, your gestures will change the effect settings. When you find the

"spot" you like, you may process your sound with those particular effect settings. Note that most effect plug-ins only allow
you to adjust one knob or slider at a time; Hyperprism gives you access to the entire set of controls, with a single mouse
move.

Mac versions of Hyperprism, including Hyperprism 2 for HyperEngine, Hyperprism-TDM and Hyperprism-VST
allow you to record and replay the dynamic gestures you create in the Blue Window. Unfortunately, this capability is not
possible within the current DirectX or plug-in architecture. This means that the dynamic sound changes you will hear as
you drag the mouse in the Blue Window cannot be recorded and therefore cannot be replayed. Only the current position of
the mouse will be used when setting Hyperprism-DX effect parameters.

[Table of Contents] [Next Chapter]

Hyperprism-DX

Hyperprism-DX Installation

Getting Started

This Chapter describes the procedure for installing and configuring Hyperprism-DX on your Pentium computer.
Before using Hyperprism-DX, please make sure that you have a basic knowledge of the Windows 95, Windows 98 or

Windows NT 4.0 operating system. This includes knowing how to use the mouse, windows, menus, etc. If these terms are
strange to you, please consult your operating system documentation.

Hyperprism-DX works as a plug-in with any of the compatible third-party audio editing programs. Please first install your
chosen "host" program and make sure you are familiar with its basic operations.

Hook up the audio connections between your computer/sound card and external audio system(s) so that you can monitor
and/or record audio, as necessary for your application. Make sure that you have an adequate monitoring system or
headphones so that you can make accurate judgments about sound quality and noise reduction settings.

Before Installing

When opening your Hyperprism-DX package you will find the following contents:

One CD-ROM containing the applications, documentation, sample sounds and other files

●

One registration card●
One Hyperprism-DX or Hyperprism Plug-in Pack serial number card●
One envelope bearing the Arboretum license agreement●

IMPORTANT
Please fill out your registration card and mail or fax it to Arboretum Systems as soon as possible in order to:

get FREE technical support

●

be informed of new developments and upgrades●
help shape future products●

Note that in order to receive ANY upgrades, telephone support or other assistance from Arboretum Systems, you must be a
registered user.

System Requirements: Windows

A Pentium computer with clock speed of 133 MHz or faster●
Windows 95/98 or NT 4.0●

16 MB or more total system RAM●
Windows compatible sound card●
DirectX Media 5.2 or higher (included)●

Although Hyperprism-DX may run on slower Pentiums, you will notice degraded preview performance due to over-taxing
the processor. Note however that even on the slowest machines Hyperprism-DX will Process (render the file off-line)
successfully in every case.

Compatibility

Hyperprism-DX is a plug-in for any Windows sound editing program which supports the DirectX plug-in format (also
known as ActiveMovie or DirectShow). Run Hyperprism-DX with audio software including Cakewalk's Cakewalk Pro
Audio, Sonic Foundry Sound Forge, Steinberg Cubase and WaveLab, Syntrillium Cool Edit Pro, Emagic Logic Audio and
others.

Audio Hardware

The Hyperprism-DX plug-in's audio input/output services are all provided by your DirectX compatible "host" application.
This means if your sound card already works with the audio editing software you use (Sound Forge, WaveLab, Cakewalk,
Cubase, Cool Edit, etc.) then it'll work fine with Hyperprism-DX as well. Hyperprism-DX just "talks" to the plug-in host;
any communication between the sound card and software is handled by the host application.

Setup Procedure: Windows 95/98/NT

Before beginning the installation, quit all other programs which may currently be running.

●

Insert the Arboretum CD-ROM which came in your Hyperprism-DX package into your PC's CD-ROM drive.●

The "Arboretum" volume should appear at your CD-ROM drive.

Double-click on the CD-ROM drive to open the Arboretum CD

●

Open the Hyperprism-DX folder. Note: That's the Hyperprism-DX folder, not the neighboring Ray Gun folder!●
Double-click on the Icon labeled "Setup.exe"●

You'll Enter the Setup Wizard.

Follow all on-screen directions; most of the dialogs which follow simply require a "Next" or "OK" response.

●

If the installer has detected an older (or demo) version of the Hyperprism-DX software, it will give you the choice
of deleting the old files. We recommend in every case that you go ahead and delete the old (or demo) editions.

●

If you have old/demo software to delete, you'll enter the uninstall routine.

After the de-install, or if there is nothing do delete, click past the Arboretum Installer Welcome screen.

●

The Hyperprism-DX ReadMe file is displayed. Make certain you look at the ReadMe for any last-minute feature
or compatibility notes which may have not made it into this documentation.

●

The Arboretum Systems Software License Agreement is shown. Be sure to read this agreement, it describes the
terms of our warranty and places certain restrictions on your use of this software. If you do not agree to the terms
of the agreement you can just stop right here and terminate installation. Otherwise OK the License Agreement to
continue.

●

Select the directory into which the Hyperprism-DX software will be installed.●
Select the program folder into which the Hyperprism-DX software will be installed.●

Now the installation from CD begins...●

Hyperprism-DX and the associated HTML documentation and help files will be copied to the program folder

indicated in the previous step.

The installer will ask you for your name, organization (if any) and Hyperprism-DX serial number. Name and serial
number are mandatory, organization is optional. Make sure you enter the serial number, (28 digits plus 4 dashes)
including the dashes, in the correct sequence. Don't confuse the serial number with your product's registration
number, which may be the shorter number (in larger type) on your Hyperprism-DX registration card. Any errors
will result in failure.

●

The final window in the installer sequence is a ReadMe regarding DirectX. You'll need Direct X Media 5.2 or
higher, which is included on the CD and is also available by download from Microsoft's web site.

●

If you view the Program folder you'll see the HTML documentation and the Hyperprism-DX Uninstaller. The
Uninstaller can be used if you ever need to remove the Hyperprism-DX program files and documentation. Note that the
Hyperprism DirectX effects are not directly visible here...

The Hyperprism-DX effects will appear right along with any other DirectX plug-ins you may have in your audio
editing program's plug-ins sections.

You're now ready to use the Hyperprism-DX!

●

Windows installation support notes

Problems? If any unexpected error messages come up during the course of installation, or if the Setup fails to install or
serialize the Hyperprism-DX plug-in and stand-alone editions, immediately quit the Setup wizard, quit any other programs
which may be running and Restart your computer.

Once restarted, run the Setup again and follow the preceding installation steps as directed. Also make sure you're using the
correct Arboretum product serial number. Arboretum's Ray Gun and Hyperprism-DX are each sold separately, and each
require their own unique serial numbers.

If Trouble Persists: Link over to the Troubleshooting chapter of this manual. Also take a look at the Support frame up on
the Arboretum web site <http://www.arboretum.com> for the latest technical notes and troubleshooting tips. If all else fails

either email [e-mail] or phone our service line during our regular weekday business hours, 10 am to 6 pm
Pacific: [phone]

[Last Chapter][Table of Contents] [Next Chapter]

Hyperprism-DX

Controlling Hyperprism

The Hyperprism-DX screen is made up of four main parts;The Blue Window (the center), the Sliders (top), the level
(lower left) and playback, process and presets area (the right).

To close the Hyperprism-DX window, simply click the Cancel button in the upper right area of the screen.

The Blue Window

The main part of Hyperprism-DX's screen is the Blue Window. By clicking and dragging your mouse in the Blue
Window's "Play Zone", you may adjust up to five effect parameters simultaneously. Some parameters could be
manipulated by horizontal mouse motions while others could be controlled by vertical ones. You can change these
assignments to suit your working style and the effects you are trying to achieve. The sliders at the top of the screen
determine the effect parameters that are controlled by the Blue Window.

The Sliders

The Sliders are used to set effect parameters. They can be individually adjusted directly with the mouse, or they can be set
to correspond to horizontal or vertical mouse movements in the Blue Window.

Note the small blue button and the large unit button on the left of each of the parameter sliders above the Blue
Window. Clicking the unit button will cycle the small blue button through three possible states, shown by a small green
bar. The three choices are vertical control, horizontal control or off.

When the green bar appears horizontally across the top of the blue button (as shown above), that slider will be

controlled by horizontal mouse movements in the Blue Window.

Clicking the unit button a second time will cause the green bar to appear vertically at the left side of the blue button

and the corresponding slider will be controlled by vertical mouse movements in the Blue Window.

Finally, clicking the unit button once more will cause the little green bar to disappear. In this case, this slider will be

unaffected by movements in the Blue Window.
How might this feature be used? For example, you may wish to control a Hall Reverb by assigning Diffusion and

Brightness to horizontal mouse movements while Feedback is assigned to vertical mouse movements.

Current Parameter Value

To the right of each parameter slider is two numeric fields which reflect the slider's maximum and Current Value,
respectively. As you move any parameter slider its current value updates in this field. Double-click here to highlight the
field and type in a new Current Value.

Changing Slider Ranges

Sometimes, the default range of values from one end of a sliders travel to the other may be larger than you'd like. If so, you
may decrease the minimum or maximum settings by entering new values in the the minimum and maximum parameter
value numeric fields at either end of each slider.

Changing the range or the current parameter value can be done by double-clicking in any numeric field and typing the
precise value you want.

Output Level

At the left side of the screen you will find Hyperprism-DX's level control.

Faders

The faders are graphic potentiometers that control the gain or attenuation of the signal. When an effect is on, Hyperprism's
faders affect the level at the output of the effects process (i.e., post-effect).

Each channel is independent. The fader palette contains two faders, left and right. These can be independent or grouped
together. The faders are aligned to 0 dB by default. Fader values range from -18 dB to + 18 dB.

Three buttons are located below the faders, two are labeled "O dB." Click either to reset the fader to 0. To lock the faders
simply click the middle button and then when you move one fader the other will follow.

You can move the faders during playback. If you want to change the gain, be prudent when increasing the level, as
you might overload ears and your loudspeakers. If you saturate your digital-to-analog converter hardware, the red LEDs in
the peak meters light up. They remain lit until you explicitly turn them off with the reset button at the top of the meters.

Caution-Watch Your Levels!

When using Hyperprism-DX, please use caution when setting your listening levels. Some of Hyperprism's effects can add
large amounts of gain to your original sound. Therefore, it is very important that you are aware of your overall monitor
levels to protect your speakers, and most importantly, your hearing from unexpected loud sounds.

Using high-Q filters or echo effects with large amounts of feedback are two ways that louder-than original sounds can be
created.

You may use Hyperprism's output level faders to adjust the overall output volume of the program. However, different Blue
Windows may produce sound at widely varying levels, so if you are using effects that result in high-gain output, use
caution to avoid unexpected loud sounds.

Preview and Process

These controls are parts of your DirectX compatible application. You may find preview, process and preset controls.

Preview

The Preview control causes Hyperprism-DX to begin looped playback of your previously selected audio. Playback will
continue until the Preview button is clicked a second time or the Stop button is hit.

Bypass

Toggling the Bypass control lets you Preview your original sound with or without the effects of the current
Hyperprism-DX settings.

Processor OK

Clicking the Process button stops preview playback and applies the current Hyperprism-DX settings to your previously
selected audio. Depending on the length of audio you selected, processing could take a few moments.

You may wish to close Hyperprism-DX and reselect a new range of audio (perhaps the entire file), then re-open
Hyperprism-DX, before Processing. Only the currently selected audio is processed!

Cancel

The "Cancel" button closes the Hyperprism-DX window.

Save/Save As

Clicking the Save button save a Preset containing the current control settings under any name you choose.

Delete

The Delete button erases the current preset. Note that you can't delete the factory presets.

Help

Clicking the Help button give you access to the Hyperprism-DX help files, which were derived from the manual you're
now reading.

Post-Roll

Some Hyperprism-DX effects can extend the length of your original sound. For example, adding reverb to a sound will
almost certainly increase its length.

However, Hyperprism-DX will stop playback when the end of the original sound's duration is reached . In this case, reverb
tails, lingering echoes and similar effects can have their final decay unpleasantly truncated.

By increasing the length of the original sound in your editing program, the lingering parts of an effect can be
preserved. Just leave some amount of post-roll time at the end of the waveform when selecting a range for processing in
your sound editing program, or append some silence to the sound file if your sound runs right up to the end of file.

[Last Chapter][Table of Contents] [Next Chapter]

Hyperprism-DX

Using Presets

Presets, which are combinations of Hyperprism settings that you can save and recall for later use, are handled by the
DirectX host application (your sound editing software). Hyperprism-DX has full preset support; just bear in mind that
presets are implemented differently by each audio software manufacturer. Fortunately, the concepts and core features
remain the same across all applications.

Presets let you store all the settings except the position of the Blue Window cursor. This feature allows you to create a
library of effects settings that you can reuse at will.

The Preset Menu

Saving and loading Presets is done with the Presets menu,which is part of your DirectX compatible application. Just select
any Preset from the pop-up menu to audition its settings.

Each effect type has its own list of Presets.Therefore, the contents of the Presets pop-up menu will change
depending on which Hyperprism Process is currently selected.

Saving A Preset

If you find a combination of settings you like, save it as a Preset using the Save or Save As function.

As soon as a Preset is saved, it becomes available to all other Blue Windows of the same process type. This means
that if you create settings you like, you may store them as a Preset and immediately load that Preset in a new Blue
Window.

Deleting A Preset

If you decide you no longer want a previously stored Preset, it can be deleted (except for the factory Presets).
Logic Audio 3.5: No support for effect presets in this version of Logic; we're in contact with the Emagic folks about this

issue and hope to see updates in the near future.

[Last Chapter] [Table of Contents] [Next Chapter]

Hyperprism-DX

Hyperprism Processes

Click on any link below for detailed description of each Hyperprism effect.

Hyperprism Filter Processes

Low Pass●
High Pass●
Band Pass●
Band Reject●

Hyperprism Modulation Processes

Vocoder●
Frequency Shifter●
Phaser●
Flanger●
Chorus●
Ring Modulator●
Tremolo●
Vibrato●

Hyperprism Delay and Reverb Processes

Single Delay●
Multi Delay●
Echo●
HyperVerb●
Room Reverb●
Hall Reverb●

Hyperprism Stereo Processes

Pan●
Auto Pan●
Quasi Stereo●

Stereo Dynamics●
More Stereo●
M-S Matrix●

Hyperprism Miscellaneous Processes

New! Harmonic Exciter●
New! Bass Maximizer●
New! Tube/Tape Saturation●

Pitch Changer●
Noise Gate●
Compressor●
Limiter●
Sonic Decimator

Go to Effects: [Filters][Modulators] [Delay and Reverb] [Stereo] [Misc Effects]
[Table of Contents]

●

Hyperprism-DX Filter Processes

Low Pass●
High Pass●
Band Pass●
Band Reject●

Low Pass

A low pass filter passes only low frequencies. An important property of a low pass filter is its cutoff frequency. By
convention, this is the point in the frequency range at which the filter reduces the signal to -3 dB of its original power. (In
visual terms, a -3 dB reduction in a waveform displayed on your monitor will result in a signal that appears to be half the
peak-to-peak height of the original.)

Spectral components that are attenuated below the cutoff of a filter are said to be in the stop band of a filter. Those above
the half-power point are said to be in the pass band of the filter.

In an ideally sharp filter, the cutoff frequency is a kind of brick wall: anything outside it is maximally attenuated, dividing
the frequency response neatly into a pass band and a stop band. In actual filters, the slope of the filter leading up to the
cutoff frequency is not linear (there is a slight ripple in the frequency response), and the area between the pass band and
the stop band is called the transition band.

The steepness of a filter's slope is usually specified in terms of decibels of attenuation or boost per octave, abbreviated
"dB/octave." For example, a 6 dB/octave slope on a low pass filter makes a smooth attenuation (or roll-off), while a 90
dB/octave slope makes a sharp cutoff. The use of a smooth or sharp slope depends on the musical situation. For example, a
sharp band reject filter might be needed to completely eliminate a tone centered at a particular frequency, while a gentle
low pass filter could be the most unobtrusive way of attenuating background noise in the high frequency range.

Parameters

Frequency

Select the cutoff frequency for the low pass filter, from 20 Hz to 20,000 Hz. Signal above cutoff frequency will be filtered
out.

Q Factor

Q factor, from 0.1 to 100. The Q determines the sharpness of the response of the filter, corresponding to its degree of
resonance. The greater the Q, the sharper the filter. When the Q is high, the frequency response is sharply focused around a
peak (resonant) frequency. A high Q setting will tend to reduce the total signal level coming out of the filter.

Low pass filter response curves for two different values of Q. A low Q filter has a smooth roll off. The high Q filter has a

resonance peak before the cutoff frequency.

Smoothing

Example

In your host application, locate the Provence.wav sound file, and play it. You should hear crickets while a propeller
plane passes in the sky.

Select the Low Pass filter from the plug-ins menu.

A Blue Window appears.Click on the Preview button to hear the effect.

Change the 20,000 maximum value in the Frequency scale to 2000 in order to get a more accurate definition.

Adjust the cutoff frequency of 450 Hz and Q factor to 5.

You should be hearing the plane only. Note that if you raise the cutoff frequency, you'll hear the crickets coming in.

Cutting the high frequencies drops the overall volume. You can use the Faders to add some gain and correct the loss.

High Pass

A high pass filter only passes high frequencies. That is, it attenuates frequencies below the specified cutoff frequency. (For
more on general properties of filters, see the description of the Low Pass filter.)

Parameters

Frequency

Frequency scale, from 13 to 20,000 Hz.

Q Factor

Q factor, from 0.1 to 100. (See the previous explanation of Q for the low pass filter.)

High pass filter response curves for two different values of Q. A low Q filter has a smooth roll off. The high Q filter has a

resonance peak before the cutoff frequency.

Smoothing

Example

In your host application, locate the Provence.wav sound file and play it. You should hear crickets while a propeller
plane passes in the sky.

Select the High Pass filter from the plug-ins menu.

A Blue Window appears.Click on the Preview button to hear the effect.

Change the 20,000 Hz maximum value in the Frequency scale to 500 in order to get a more accurate definition.

Move the Frequency slider along its range while listening to the effect.

As you move the cutoff frequency from low to high, the low frequencies are attenuated more and more until you

stop hearing the sound of the plane.

Note that the overall level has gone down.You can use the Faders to amplify the signal.

Band Pass

A band pass filter passes a certain band of frequencies within an upper bound and a lower bound. Frequencies above and
below this band are attenuated. The difference between the higher and lower cutoff frequencies in a band pass filter is the
bandwidth of the filter. The center frequency of a band pass filter is the maximum point of amplitude.

Parameters

Frequency

Frequency range, from 13 Hz to 20,000 Hz.

Q Factor

Q factor, from 0.1 to 100. It determines the sharpness of the filter, and is akin to the resonance factor. Q can be defined
precisely for a band pass filter as the ratio of the center frequency to the spread of its -3 dB point (cutoff point) bandwidth.

where fcenter is the filter's center frequency, fhighcutoff is the upper -3 dB point, and flowcutoff is the lower -3 dB point.

When the center frequency is constant, adjusting the Q is the same as adjusting the bandwidth.

Band pass filter response curve for different Q values

When the Q is high, the filter will begin to resonate or ring at the center frequency. However, a high Q setting will
also tend to reduce the overall signal level coming out of the filter. The Q factor can be increased to a very high value, in
which case it generates a sinusoidal tone amplitude of which varies according to the input signal. If this signal is loud
enough to cause distortion, reduce the level of Hyperprism-DX's faders.

Smoothing

Example

In your host application, locate the Airport.wav sound file and play it. You should hear an announcement recorded
in the Paris Orly airport that contains an additional signal at 1050 Hz. The Band Pass filter lets one isolate this frequency
and eliminate everything else. In order to do this:

Select the Band Pass filter from the DirectX menu.

A Blue Window appears.Click on the Preview button to hear the effect.

Modify the Frequency range to min/max settings of 500 and 2000 Hz, and the Q factor range from 10 to 100.

Adjust the Frequency and Q Factor parameters until only the 1050 Hz tone is heard.

When the frequency setting is at 1050 and the Q between 50 and 100, you should hear only the tone.

Band Reject

A band reject filter strongly attenuates frequencies within a bandwidth centered around a selected frequency. It passes
frequencies above and below this bandwidth. In this sense, it is the inverse of a band pass filter, since the center frequency
of a band reject filter is the minimum point of amplitude.

Approximate response curves for the Band Reject filter at a fixed center frequency, but with two different Q values. At a Q

of 1, the dip in the center is smooth. At a Q of 10, two resonance peaks build up around the rejected band.

Parameters

Frequency

Selects the center frequency of the rejected band. The scale is 13 Hz to 20.000 Hz.

Q Factor

Q factor, from 0.1 to 100. Determines the sharpness of the cutoff of the filter. The higher the Q, the sharper the cutoff. See
the description of Q for the Band Pass filter.

Smoothing

Example

In your host application, locate the Airport.wav sound file and play it. You should hear an announcement recorded
in the Paris Orly airport that contains an additional signal at 1050 Hz. The Band Reject filter lets one eliminate this
frequency. In order to do this:

Select the Band Reject filter from the DirectX menu.

A Blue Window appears.

Click on the Preview button to hear the effect.

Modify the Frequency scale to min/max settings of 1000 and 1100 Hz in order to get a more accurate definition.